This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from my application SYSTEM FOR CONTROLLING TELEPHONY DEVICE BUS IN A SWITCHING SYSTEM filed with the Korean Industrial Property Office on Aug. 19, 1998 and there duly assigned Serial No. 33659/1998.
1. Field of the Invention
The present invention relates to a switching system, and more particularly to a system for controlling telephony device control buses by sub-controllers in a switching system.
2. Description of the Related Art
In an earlier switching system, the telephony device buses (TD-buses) are controlled by a main controller and separate sub-controllers by communicating through an HDLC (High-level Data Link Control) or IPC (Interprocess communication) protocol. For example, a TDX-10 series system has a main processor hardware block (MPH) as the main controller and a peripheral processor hardware block (PPH) as the sub-controllers. A TDX-10 series system has a TD-bus control system which includes a main controller connected through a P-bus with a plurality of sub-controllers for IPC. Each of the sub-controllers has four ports connected through a TD-bus with telephony devices.
In operation, each sub-controller transmits the state information of the telephony device to the main controller by means of the IPC. Then, the main controller sends a command for controlling the telephony device to the corresponding sub-controller by means of the IPC. The sub-controller controls the telephony device according to the command. Thus, the control system employing such a serial transmission protocol is divided into two control levels to control the telephony devices by means of load sharing. This increases the number of the circuit cards needed for the control system, thereby degrading reliability of the data transmission on multiple bus stages. Besides, the protocol control and program job for IPC complicates the control of the telephony device, adversely affecting the performance of the control system.
Each of the following patents discloses features in common with the present invention but do not teach or suggest a system for controlling a telephony device bus in a switching system as in the present invention: U.S. Pat. No. 5,371,736 to Evan, entitled UNIVERSAL PROTOCOL PROGRAMMABLE COMMUNICATIONS INTERFACE, issued on Dec. 6, 1994; U.S. Pat. No. 5,265,237 to Tobias et al., entitled BYTE SWAPPING APPARATUS FOR SELECTIVELY REORDERING BYTES OF AN N-BIT WORD COMMUNICATED BETWEEN AN AT COMPUTER AND VME BUS, issued on Nov. 23, 1993; U.S. Pat. No. 5,321,818 to Wendling et al., entitled SYSTEM FOR ARBITRATING FOR ACCESS ON VME BUS STRUCTURES, issued on Jun. 14, 1994; U.S. Pat. No. 5,414,814 to McKim, entitled I/O INTERFACE BETWEEN VME BUS AND ASYNCHRONOUS SERIAL DATA COMPUTER, issued on May 9, 1995; U.S. Pat. No. 5,748,916 to Conway et al., entitled VXIBUS DEVICE WHICH INTELLIGENTLY MONITORS BUS CONDITIONS AND BEGINS EARLY CYCLES FOR IMPROVED PERFORMANCE, issued on May 5, 1998; U.S. Pat. No. 5,590,372 to Dieffenderfer et al., entitled VME BUS TRANSFERRING SYSTEM BROADCASTING MODIFIERS TO MULTIPLE DEVICES AND THE MULTIPLE DEVICES SIMULTANEOUSLY RECEIVING DATA SYNCHRONOUSLY TO THE MODIFIERS WITHOUT ACKNOWLEDGING THE MODIFIERS, issued on Dec. 31, 1996; and U.S. Pat. No. 5,898,888 to Guthrie et al., entitled METHOD AND SYSTEM FOR TRANSLATING PERIPHERAL COMPONENT INTERCONNECT (PCI) PEER-TO-PEER ACCESS ACROSS MULTIPLE PCI HOST BRIDGES WITHIN A COMPUTER SYSTEM, issued on Apr. 27, 1999.
It is an object of the present invention to provide a system for controlling the TD-bus connected to telephony devices.
According to an aspect of the present invention, a system for controlling a TD-bus connected to telephony devices comprises: a Versa Module European (VME) bus, a VME slave card connected through the TD-bus to the telephony devices, and a main controller connected through the VME bus to the VME slave card to control the telephony devices. The main controller generates a control command transferred through the VME slave card to the telephony devices. The VME slave card stores the resultant data obtained by controlling the telephony devices, and the main controller controls the TD-bus according to the resultant data.
The present invention will now be described more specifically with reference to the drawings attached only by of example.